Historians ask three essential questions. First, What happened? This question is about assembling a richly detailed Chronology of events. Second, Why did it happen? This is about Causation and historians never accept single-factor explanations for why things happened. Third, What difference did it make that it happened? This is about Consequence and, as with Causation, there is never just one result. This can be mantra-fied as either What?/Why?/So What? Or as Chronology/Causation/Consequence.
William Galston provides a good example of historical thinking in a rapid overview of the politics and economics of the last thirty years.
What Happened? From 1990 through 2000, the American economy expanded rapidly and the fruits of growth received a wide distribution as real wages increased. Growing industrial productivity did not reduce the manufacturing labor force; instead it raised wages. On New Year’s Day 2001, there were about 17 million people holding down manufacturing jobs in the United States. Between January 2001 and June 2009, the United States lost 5.4 million manufacturing jobs. That’s just shy of one-third of the industrial manufacturing jobs. Gone in less than a decade. American manufacturing had long been dispersed into smaller cities and rural areas. The biggest shocks were felt in areas outside the main media consumer markets.
Why did it happen? First, the Clinton Administration (1992-2000) adopted a policy mix of extending the open world market economy that had been created under American leadership after the Second World War. It would reach out from its core American, Western European, and East Asian strongholds to the lands where Marxist economics had been discredited. In practice, this meant Eastern Europe and Russia, China, and leftist governments inthe Developing World.
Second, contrary to their intent, these policies actually harmed American interests. Capitalists didn’t invest in ways that were entirely productive and efficient; industries that were essential for American national security and/or supply chains languished or were off-shored; and China, in particular, took advantage of its favored position in the World Trade Organization (WTO). The result of these policies came in a “hollow[ing] out” of American manufacturing.
Why does it matter? For one thing, these developments stimulated a “populist revolt” in the United States. This ran from the “Tea Party” dissidence within the Republican Party during the Obama Administration to Trumpism. In Democratic rhetoric, this threatens democracy.
For another thing, Jake Sullivan, President Biden’s national security adviser, has announced a new “modern national industrial strategy.” The goals of that strategy will be to strengthen the industrial foundations of national security, promote economic growth, and create a lot of well-paying jobs to replace those lost in the lost decades that began this century. The instruments will be strategic, rather than general, agreements on tariffs and trade, and subsidies. Commerce Secretary Gina Raimondo’s shepherdessing of the Biden Administration’s semi-conductor manufacturing efforts foreshadows these larger intentions.
It’s an honest piece of History. It is far from being a complete account of what happened or why it happened. It endorses, perhaps too easily, one party’s program of great consequence.
 William Galston, “Biden’s ‘Foreign Policy for the Middle Class’,” WSJ, 31 May 2023. The customary American blurring of middle-class and working-class is here on display.
 Total civilian labor force was 143 million. See: U.S. labor force 1990-2022 | Statista